Chemiluminescent smokes



3,496,111 CHEMILUMINESCENT SMOKES Urho A. Lehikoinen, Wayne, Mich., assignor to Ethyl Corporation, New York, N.Y., a corporation of Virginia No Drawing. Filed June 29, 1966, Ser. No. 561,337 Int. Cl. C09k 3/30, 1/02 US. Cl. 252188.3 7 Claims ABSTRACT OF THE DISCLOSURE Chemiluminescent smokes are produced by reacting water with a composition consisting essentially of (1) an amine complex of an aluminum alkyl, and (2) a chemi luminescent agent. A typical aluminum alkyl complex is that produced by reacting hexamethylenetetramine with triethylaluminum; an exemplary chemiluminescent agent is tetrakis(dimethylamino)ethylene.

This invention pertains to chemiluminescent smokes containing an alkyl aluminum and a tetrakis(di-loweralkylamino)ethylene. These smokes are visible by day and at night.

An object of this invention, which is to prepare a nightvisible smoke, is satisfied by providing compositions consisting essentially of These compositions yield chemiluminescent smoke clouds when admixed with water. The method of water mixing is not critical. The smoke agent may be injected underneath the surface of water to yield a cloud of chemiluminescent smoke above the surface of the water. Alternatively the smoke agent can be merely admixed with water by shaking the agent and Water in a vessel. Another method for contacting the agent with water is to introduce a stream of the agent into a water spray. Moreover, the water may be atmospheric, the smoke agents of this invention are sensitive to high humidity.

One essential ingredient in the smoke compositions of this invention is an aluminum compound of the types given above. Preferably, all alkyl radicals bonded to the aluminum atom are identical. Most preferably, these alkyl radicals are solely composed of carbon and hydrogen and have up to 4 carbon atoms. Typical examples of alkyl aluminums which are applicable in this invention are trimethyl aluminum, triethyl aluminum, diethylaluminum hydride, methyl diethyl aluminum, triisopropyl aluminum, tri-sec-butyl aluminum, and the like.

For the purposes of this invention the aluminum alkyl is complexed with an amine. A wide variety of amines can be employed. The exact nature of the amine is not critical provided it can complex with the aluminum compound and is devoid of substituent groups which lead to deleterious side effects. Preferably, the amines are selected from hexamethylenetetramine and tetraloweralkyl ethylene diamines. (For the purpose of this invention, lower alky signifies alkyl radicals of one to four carbons.)

The complexing of the alkyl aluminum with an amine is readily carried out by simply mixing the amine and the alkyl aluminum under anhydrous conditions and in States atent the presence of an inert atmosphere. Typically, nitrogen is used to provide the inert atmosphere. However, other inert gases such as argon and neon can be employed, if desired. Best results are obtained when all of the alkyl aluminum is complexed with an amine. When using a diamine, at least one-half mole of amine is employed for each mole of alkyl aluminum. Similarly, when a tetramine is employed, at least one-quarter mole of amine is employed for each mole of alkyl aluminum. In other words, the ratio of amine to aluminum is the inverse molar ratio of the number of amine nitrogens to aluminum atoms.

It is not necessary to employ an exactly chemiequiv-alent amount of amine and alkyl aluminum. An excess of amine or alkylaluminum can be used. It is convenient to employ up to 5 equivalents of amine for each equivalent of alkyl aluminum.

After the trialkyl aluminum is complexed with the amine it is then mixed with an amount of tetrakis(diloweralkylamino)ethylene which is sufficient to yield a final preparation containing from 20 to 50 weight percent of tetrakis compound. The mixing of the complex with the tetrakis compound is conveniently carried out using simple mixing procedures. As in the case of complexing, a slight amount of heat may be beneficial, that is, it may be desirable to heat up the mixture to a temperature within the range of 3050 C.

As pointed out above, the chemiluminescent smoke formulations of this invention yield smoke clouds which are visible at night when admixed with water. The water need not be pure; natural waters such as lake, river or sea water can be employed as can muddy or wet earth. In addition, the water may be chemically-bound, that is, waters of hydration. When using chemically-bound water, a compound which preferentially contains a large amount of waters of hydration is employed. Preferred compounds containing waters of hydration are alums. Typical alums which may be used are described on pages 196-199 of the 8th edition of Langes Handbook of Chemistry, Handbook Publishers, Inc., Saudusky, Ohio (1952).

To further illustrate the invention, the following nonlimiting examples are presented. Unless otherwise indicated, all parts are by weight.

Example 1 Weight percent Hexamethylenetetramine 13.8 Triethyl aluminum 45 Tetrakis(dimethylamino)ethylene 39.5 Tetrahydrofuran 1.8

The tetrahydrofuran is not a critical ingredient but aids in the solubilization of the hexamethylenetetramine. Usually about one to three percent of such a solubilization agent is eflicaciously employed. Besides tetrahydrofuran, another typical solubilizing agent that can be used is dioxane. ,Similarly, many other ethers can be employed.

The resultant smoke formulation yields a chemilumi' nescent smoke when admixed with water. For example, equal volumes of agent and water when admixed together yield a chemiluminescent smoke. Furthermore, such a smoke is produced when one volume of agent is injected under the surface of approximately 10 volumes of Water without artificial stirring. Thirdly, the formulation yields a chemiluminescent smoke when 50 parts of the formula tion are added to 100 parts of [CI'2(SO4)3'K2SO424H20] Example 2 Example 3 Equimolar complexes of tetramethylenediamine with triethyl aluminum were prepared using the procedure of Example 1. They Were admixed with sufficient quantities of tetrakis(dimethylamino)ethylene to yield formulations containing 20, 30, 40 and 50 Weight percent of the tetrakis compound.

Results indicate that the best smokes are produced when the concentration of the tetrakis compound is from 30 to 40 weight percent. Similar formulations are prepared by substitution of triisopropyl aluminum, tributyl aluminum or diethyl aluminum hydride for the triethylaluminum, tetrakis(dibutylamino)ethylene for the tetrakis(dimethylamino)ethylene, and the ethyl, propyl and butyl homologues of N,N,N',N-tetramethyl ethylenediamine for that compound.

The smokes of this invention which are visible at night have many utilities. For example, they can be employed for marking purposes in sea rescues. Similarly, they may be used to direct artillery fire or aerial bombardments.

An important aspect of this invention is that the smokes are visible by day and at night. Hence, they have daytime and nighttime utilities. Accordingly, the compositions of this invention have a dual function. It is believed that this dual function is not accomplished by smokes and flares presently in use. Moreover, the residue after dissemination by sublimation in water is a chemiluminescent film which floats on the surface of the water. This film is colored and typically orange. Since it is also visible in daylight, this aids in marking.

Having fully described the novel compositions of this invention, their method of preparation and their utility,

4 it is desired that the scope of this invention be solely limited by the lawful extent of the appended claims.

What is claimed is:

1. A chemiluminescent smoke composition consisting essentially of (a) an aluminum alkyl having the formula RRR"Al wherein R, R' and R" are alkyl radicals of 1 to 4 carbon atoms, said aluminum alkyl being complexed with a chemically equivalent amount of (b) an amine selected from the class consisting of hexamethylenetetramine and N,N,N,N'-tetraloweralkyl ethylenediamines, and admixed with (c) from 20-50 weight percent of a tetrakis(di-loweralkylamino)ethylene.

2. A smoke composition of claim 1 wherein the aluminum alkyl is triethyl aluminum.

3. A smoke composition of claim 2 wherein said tetrakis(di-loweralkylamino)ethylene is tetrakis(dimethylamino)ethylene.

4. A smoke composition of claim 3 wherein said amine is hexamethylenetetramine.

5. A smoke composition of claim 3 wherein said amine is N,N,N,N-tetramethyl ethylenediamine.

6. A method for producing a chemiluminescent smoke, said method comprising mixing a smoke composition of claim 1 with water.

7. A method of claim 6 wherein said water is from an alum having the formula References Cited UNITED STATES PATENTS 3,309,268 3/ 1967 Sherman 252-305 3,311,564 3/1967 Cline 252-1883 3,352,894 11/1967 Crain et a1. 260-448 OTHER REFERENCES Zeiss, Organometallic Chemistry, Reinhold Pub. Co. (1960), p. 202.

JOHN D. WELSH, Primary Examiner US. Cl. X.R. 

